VHS pressure relief valves available from WAM Australia are designed as a safety feature for silos to deal with abnormal pressure conditions.
Sudden excess or suction pressure inside the silo structure must be dealt with instantly. Even though the VHS pressure relief valve ideally should never have to go into action, it must be efficient and reliable to meet any sudden eventuality.
VHS pressure relief valves consist of a cylindrically shaped metal body with clamp connection spigot to the silo, an exhaust outlet spout for duct connection, an elastic diaphragm to re-establish pressure balance instantaneously, a counterweight kit to keep the valve closed under normal conditions, and a weather protection cover.
The special double-acting diaphragm, which is pervious to air deals with both excess and suction pressure relief. The diaphragm is designed to avoid blockage as well as the formation of material crusts.
The counterweight-loaded VHS-type pressure relief valve has one decisive advantage over the VCP, the other valve type manufactured by WAM. Due to the moment of inertia of the helical springs on the VCP, pressure balance is re-established extremely quickly but not instantaneously.
VHS pressure relief valves do the job in real time by achieving perfect pressure balance through interplay of pressure on different surface areas on both sides of the diaphragm fitted inside the valve housing.
In the event of excess pressure this interaction enables air from inside the silo to flow back into the atmosphere while in the case of suction pressure, the air penetrates from the atmosphere into the silo.
Key features of VHS pressure relief valves:
- Casing in carbon steel (VHS2731B), painted RAL 7001 (silver-grey) or 304 stainless steel (VHS2732B)
- Body diameter: 273mm
- Air volume up to 5,000m³/h
- Exhaust outlet spout for connection with centralised suction system
- Preset for a maximum negative pressure of -0.005 bar and maximum excess pressure of +0.05 bar
- Can be set at a maximum excess pressure ranging from +0.02 bar to +0.08 bar if required
- Weight: 22kg